Chemical composition and biological properties of Ipomoea procumbens

ABSTRACT Natural products have been the most valuable source of chemical compounds in the discovery of novel medicines. Secondary metabolites from terrestrial and marine organisms have found considerable use in the treatment of numerous diseases and have been considered lead molecules both in their natural form and as templates for medicinal chemistry. Brazil has an exceptionally rich biodiversity, and a valuable source of secondary metabolites that can be useful for the development of bioproducts. Ipomoea species, Convolvulaceae, are mostly found in tropical and sub-tropical regions, including South America and many are used for nutritional and medicinal purposes. Ipomoea procumbens Mart. & Choisy is endemic from South America, and this is the first study reported on the chemical composition and biological activities of this species. The present work reports the tentatively identification of natural products present in the extracts using a high performance liquid chromatography-high resolution mass spectrometry method. Additionally, the antioxidant and antifungal biological activities of the leaves, roots and steams extracts and fractions of this species were evaluated. While for the antioxidant activity the hydromethanol fractions (leaves, stem and roots) were more active, the methanol fractions of leaves and stem provided better results for the antifungal assay.

Evaluation of acetylcholinesterase inhibitory activity of Brazilian red macroalgae organic extracts

Abstract Alzheimer's disease affects nearly 36.5 million people worldwide, and acetylcholinesterase inhibition is currently considered the main therapeutic strategy against it. Seaweed biodiversity in Brazil represents one of the most important sources of biologically active compounds for applications in phytotherapy. Accordingly, this study aimed to carry out a quantitative and qualitative assessment of Hypnea musciformis (Wulfen) J.V. Lamouroux, Ochtodes secundiramea (Montagne) M.A. Howe, and Pterocladiella capillacea (S.G. Gmelin) Santelices & Hommersand (Rhodophyta) in order to determine the AChE effects from their extracts. As a matter of fact, the O. secundiramea extract showed 48% acetylcholinesterase inhibition at 400 μg/ml. The chemical composition of the bioactive fraction was determined by gas chromatography–mass spectrometry (GC–MS); this fraction is solely composed of halogenated monoterpenes, therefore allowing assignment of acetylcholinesterase inhibition activity to them.

Antibacterial, antifungal and cytotoxic activities exhibited by endophytic fungi from the Brazilian marine red alga Bostrychia tenella (Ceramiales)

Abstract Marine environment is one of the most important sources regarding natural products research. Besides, marine microorganisms have been denominated as a talented natural source for discovery of new leads. Although the association of macroalgae and fungi has been described regarding ecological issues, there is a lack of studies about marine seaweed endophytic fungi. In this context, the goal of this study was to evaluate cytotoxic, antifungal and antibacterial activities of endophytic fungi isolated from the Brazilian marine seaweed Bostrychia tenella (J.V. Lamouroux) J. Agardh (Ceramiales, Rhodophyta). Forty-five endophytic microorganism strains were isolated from B. tenella. Crude extracts and organic fractions of ten selected strains were obtained after growth in rice medium. Samples were evaluated for cytotoxicity, antifungal and antibacterial assays. Penicillium strains showed positive results in a diversity of assays, and other five strains were active in at least one test. In addition, cytochalasin D was isolated from Xylaria sp. This alga is composed of a microbiological potential, since its endophytic strains exhibited remarkable biological properties. Moreover, cytochalasin D isolation has confirmed chemical potential of marine endophytic strains. This is the first study in which cultured fungi isolates from the Brazilian macroalga B. tenella were evaluated concerning biological properties. Results corroborated that this species could be a pharmaceutical source from marine environment. Furthermore, Acremonium implicatum is being firstly described as marine endophyte and Xylaria sp., Trichoderma atroviride and Nigrospora oryzae as marine seaweed endophytes. Thus, this work reports the first study relating detailed isolation, cultivation and biological evaluation (cytotoxic, antifungal and antibacterial) of endophytes Penicillium decaturense and P. waksmanii from the Brazilian marine red alga B. tenella. We are also reporting the isolation of cytochalasin D, a known antitumor and antibiotic compound, from Xylaria sp. strain. Despite widespread prevalence in terrestrial and marine habitats, this present work describes the first occurrence of cytochalasin D as a metabolite from marine seaweed endophyte.

Antifungal compounds produced by Colletotrichum gloeosporioides, an endophytic fungus from Michelia champaca.

In this study, eight endophytic fungi were isolated from the leaves, stems and roots of Michelia champaca. The isolates were screened and evaluated for their antifungal, anticancer and acetylcholinesterase (AChE) inhibitory activities. All of the extracts exhibited potent activity against two evaluated phytopathogenic fungi. Chemical investigation of EtOAc extracts of the endophytic fungus Colletotrichum gloeosporioides resulted in the isolation of one new compound, 2-phenylethyl 1H-indol-3-yl-acetate (1), and seven known compounds: uracil (2), cyclo-(S*-Pro-S*-Tyr) (3), cyclo-(S*-Pro-S*-Val) (4), 2(2-aminophenyl)acetic acid (5), 2(4-hydroxyphenyl)acetic acid (6), 4-hydroxy- benzamide (7) and 2(2-hydroxyphenyl)acetic acid (8). All of the compound structures were elucidated using 1D and 2D NMR and MS analyses. The antifungal and AChE inhibitory activities of compounds 1-8 were evaluated in vitro. Compound 1 exhibited promising activity against Cladosporium cladosporioides and C. sphaerospermum that was comparable to that of the positive control nystatin.

Anti-inflammatory activity of essential oil from leaves of Myrciaria tenella and Calycorectes sellowianus.

The GC-MS analysis revealed that the leaf essential oils of Myrciaria tenella (DC.) Berg and Calycorectes sellowianus O. Berg (Myrtaceae) were composed of 34 and 37 compounds, respectively. The main constituents of M. tenella oil were beta-caryophyllene (25.1%), and spathulenol (9.7%), while for C. sellowianus were guaiol (13.1%) and beta-caryophyllene (8.6%). The anti-inflammatory effect of both essential oils was investigated in vitro and in vivo. Both oils reduced significantly (p < 0.005) the treated neutrophils chemotaxis with 93% and 91% inhibition for M. tenella and C. sellowianus, respectively. However, in the systemic treatment with the essential oils (50 mg/kg p.o.) only the M. tenella oil was able to significantly reduce the carrageenan-induced paw edema with a similar effect to that observed for indomethacin (10 mg/kg), the positive control.

Chemical composition and acetylcholinesterase inhibitory activity of essential oils of Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae / Composição química e atividade inibidora de acetilcolinesterase de óleos voláteis de Myrceugenia myrcioides(Cambess.) O. Berg and Eugenia riedeliana O. Berg, Myrtaceae

The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.

A composição química dos óleos voláteis de duas espécies de Myrtaceae, Myrceugenia myrcioidese Eugenia riedeliana, ambas nativas da Mata Atlântica, foi analisada por CG-EM. A atividade inibidora de acetilcolinesterase foi determinada colorimetricamente para estes óleos. Em M. myrcioides, hidrocarbonetos monoterpênicos representaram a classe majoritária de compostos presentes no óleo volátil, sendo α-pineno o componente mais abundante e a atividade inibidora de acetilcolinesterase foi baixa, enquanto para E. riedelianaos sesquiterpenos foram observados em maiores concentrações, sendo o valerianol o componente majoritário, e este óleo apresentou uma forte atividade inibidora da enzima.

Chemical Composition and Antimicrobial Properties of Piper ovatum Vahl.

The chemical composition of the essential oil obtained from the leaves of Piperovatum Vahl by hydrodistillation was analyzed by GC-MS. The main constituents found were delta-amorphene (16.5 %), cis-muurola-4(14),5-diene (14.29 %) and gamma-muurolene(13.26%). The crude extracts and isolated compounds were screened for their antimicrobial activity. Hydroalcoholic extracts of different parts of Piper ovatum Vahl, essential oil andamides isolated from leaves were tested against Gram-positive and Gram-negative bacteria and Candida species. All extracts and amides were active against Bacillus subtilis andCandida tropicalis, including clinical strains. Essential oil was active against C. tropicalis.These amides showed an inhibitory effect on the adherence of C. tropicalis ATCC 28707 on cover glasses at 10 microg/mL, but did not show morphological alterations at the tested concentrations. Amides were identified as piperovatine and piperlonguminine, and showed MIC values of 15.6 and 31.2 microg/mL to B. subtilis and 3.9 microg/mL to C. tropicalis, and low toxic effects to Vero cells and macrophages.

Structure-activity relationship of (-) mammea A/BB derivatives against Leishmania amazonensis.

To study the structure-activity relationship of coumarin (-) mammea A/BB isolated from the CH(2)Cl(2) extract of Calophyllum brasiliense leaves, we evaluated the antileishmanial activity of natural, synthetic and derivatives of this coumarin, against promastigote and intracellular amastigote forms of Leishmania amazonensis, and their cytotoxicity to J774G8 murine macrophages. The derivatives were obtained by hydrogenation and methoxylation reactions. The compound structures were elucidated on the basis of spectroscopic data. The compounds 5,7-dihydroxy-8-(2-methylbutanoyl)-6-(3-methylbutyl)-4-phenyl-chroman-2-one (3), 7-hydroxy-5-methoxy-8-(2-methylbutanoyl)-6-(3-methylbut-2-en-1-yl)-4-phenylcoumarin (4) and 5,7-dimethoxy-8-(1-methoxy-2-methylbutyl)-6-(3-methylbut-2-en-1-yl)-4 phenylcoumarin (6) were more biologically active than the compound (-) mammea A/BB (1) (7.4 microM), with IC(50) values from 0.9, 2.4 and 1.9 microM respectively; compound (3) displayed the highest activity. The compounds mammea B/BB (2), 5,7-dimethoxy-8-(2-methylbutanoyl)-6-(3-methylbut-2-en-1-yl)-4-phenylcoumarin (5) and 5,7-dihydroxy-4-phenylcoumarin (7) were less active than (-) mammea A/BB (1), with IC(50) of 30.1, 15.1 and 60.2 microM respectively; compound (7) showed the lowest antileishmanial activity of all. Compounds (1), (3), (4) and (6) were active not only against promastigote forms of L. amazonensis, but also against intracellular amastigote forms with IC(50) of 14.3, 0.6, 34.0 and 22.2 microM, respectively. Interestingly, compound (3) showed the most antileishmanial activity of all. This study demonstrated that several aspects of the structure were important for antileishmanial activity.

Indole monoterpene alkaloids from Chimarrhis turbinata DC Prodr: a contribution to the chemotaxonomic studies of the Rubiaceae family / Alcalóides indólicos monoterpênicos de Chimarrhis turbinata DC. Prodr.: uma contribuição para os estudos de quimiotaxonomia da família Rubiaceae

The morphological parameters used to establish close connections among species taxonomically different into the Rubiaceae family is complex, mainly due to the lack of information on habitat and morphoanatomical characters in the lower hierarchic groups, for example, Chimarrhis genus. The micromolecular profile of delimited species into determined taxa can be useful to establish the boundaries among close taxonomic groups, and to indicate evolutionary phylogenetic trends into the taxa. Several indole alkaloids isolated from C. turbinata showed to be a valuable tool to support the taxonomic classification performed by Robbrecht, who established the most recent taxonomy for Rubiaceae, based on morphological characters, and concluded that Chimarrhis belong to Condamineae, and subfamily Cinchonoideae.

A utilização de parâmetros apenas morfológicos para posicionar taxonomicamente diversas espécies em sub-famílias e tribos na família Rubiaceae é bastante problemática devido à falta de informações sobre a distribuição geográfica e de características morfoanatômicas nos níveis hierárquicos mais baixos, como por exemplo, o gênero Chimarrhis. O perfil micromolecular de diferentes espécies pode auxiliar na delimitação de tribos indicando tendências filogenéticas mais completas entre as tribos das sub-famílias, já que os metabólitos secundários são expressões de adaptação, regulação e evolução de um determinado táxon. Nesse contexto, os alcalóides indólicos monoterpênicos isolados de Chimarrhis turbinata foram bastante úteis para embasar a classificação taxonômica feita por Robbrecht, em que posiciona Chimarrhis como um gênero da tribo Condamineae e subfamília Cinchonoideae.

Biciclogermacreno, resveratrol e atividade antifúngica em extratos de folhas de Cissus verticillata (L) Nicolson & Jarvis (Vitaceae) / Bicyclogermacrene, resveratrol and fungitoxic activity on leaves extracts of Cissus verticillata L. Nicolson & Jarvis (Vitaceae)

Cissus verticillata L. (Vitaceae) tem sido empregada popularmente como anti-diabética. Nessa espécie foi também detectada atividade fungitóxica. O objetivo do presente trabalho foi realizar a identificação dos compostos fungitóxicos em extratos de folhas. O extrato etanólico foi submetido a fracionamento com solventes de diferentes polaridades (hexano, clorofórmio, acetato de etila e butanol) e seu efeito antifúngico foi analisado frente a Cladosporium sphaerospermum. Os extratos em clorofórmio e acetato de etila mostraram atividade, e foram fracionados por cromatografia em coluna e cromatografia preparativa em placas de sílica, respectivamente. Três terpenóides foram isolados do extrato em clorofórmio; um deles foi identificado, por análise em CG-EM, como um sesquiterpeno, o biciclogermacreno. O composto ativo do extrato em acetato de etila foi identificado, por análises em CLAE, como o estilbeno resveratrol.

Cissus verticillata L. (Vitaceae) is popularly employed as hypoglicemic and it shows fungitoxic activity. This work aims at identification of fungitoxic compounds on extracts of leaves. The ethanol extract was partitioned using solvents of different polarities (hexane, chloroform, ethyl acetate and butanol) and its fungitoxic activity was analysed upon Cladosporium sphaerospermum. The chloroform and ethyl acetate extracts showed activity and they were fractionated by column chromatography and preparative TLC, respectively. Three terpenoids were isolated from the chloroform extract, one of them identified by GLC-MS analysis as sesquiterpene bicyclogermacrene. The active compound of the ethyl acetate extract was identified by HPLC analyses as stilbene resveratrol.

Antileishmanial activity of crude extract and coumarin from Calophyllum brasiliense leaves against Leishmania amazonensis.

Infections by protozoans of the genus Leishmania are a major worldwide health problem, with high endemicity in developing countries. The drugs of choice for the treatment of leishmaniasis are the pentavalent antimonials, which show renal and cardiac toxicity. As part of a search for new drugs against leishmaniasis, we evaluated the in vitro leishmanicidal activity of the (-) mammea A/BB. The compound (-) mammea A/BB is a coumarin-type mammea purified from a dichloromethane crude extract of leaves of Calophyllum brasiliense Cambess (Clusiaceae). The isolated compound was characterized using spectral analyses by UV, infrared, nuclear magnetic resonance of (1)H, (13)C, distortionless enhancement by polarization transfer, correlation spectroscopy, heteronuclear multiple bond correlation, and heteronuclear multiple quantum coherence. The compound (-) mammea A/BB showed significant activity against promastigote and amastigote forms of L. amazonensis, with IC(50) (50% inhibition concentration of cell growth) at a concentration of 3.0 and 0.88 mug/ml and IC(90) (90% inhibition concentration of cell growth) of 5.0 and 2.3 microg/ml, respectively. The coumarin (-) mammea A/BB showed no cytotoxicity against J774G8 macrophages in culture, when it was tested at high concentrations that inhibited promastigote forms. Electron microscopy studies revealed considerable ultrastructural changes when promastigote forms of L. amazonensis were treated with 3.0 microg/ml of the coumarin (-) mammea A/BB for 72 h. We observed significant changes such as mitochondrial swelling with concentric membranes in the mitochondrial matrix and intense exocytic activity in the region of the flagellar pocket. Other alterations included the appearance of binucleate cells and multiple cytoplasmic vacuolization. These results showed that (-) mammea A/BB is a potent growth inhibitor of L. amazonensis and caused important changes in the parasite's ultrastructure. This study provided new perspectives on the development of novel drugs with leishmanicidal activity obtained from natural products.

Search for antifungal and anticancer compounds from native plant species of Cerrado and Atlantic Forest

Bioactivity-guided fractionation of several bioactive exttracts obtained from Cerrado and Atlantic Forest plant species led to the isolation of potent DNA-damaging piperidine 1-5 and guanidine alkaloids 6-9 from Cassia leptophylla and Pterogyne nitens respectively, two common Leguminosae from Atlantic Forest. By means of biotechnological approach on Maytenus aquifolium, a species from Cerrado, moderate DNA-damaging sesquiterpene pyridine alkaloid 10-11 was isolated. Bioassay-guided fractionation on Casearia sylvestris, a medicinal plant species found in Cerrado and Atlantic Forest, led to the isolation of clerodane diterpenes 12-13 which showed effect on DNA. In addition, we have reported several interesting potent antifungal iridoids: 1beta-hydroxy-dihydrocornin (14), 1alpha-hydroxy-dihydrocornin (15), alpha-gardiol (16), beta-gardiol (17), plumericin (18), isoplumericin (19), 11-O-trans-caffeoylteucrein (20); ester derivative:2-methyl-4-hydroxy-butyl-caffeoate (21), amide N-[7-(3ï, 4ï-metrylenedioxyphenyl)-2Z, 4Z-heptadienoyl] pyrrolidine (22) and triterpene viburgenin (23).